package com.mlick.a.csnotes;

import java.util.HashSet;
import java.util.Set;

/**
 * @author lixiangxin
 * @date 2019/12/9 10:42
 **/
public class T3 {

    //运行时间	占用内存
    //28ms	    9540K
    // Parameters:
    //    numbers:     an array of integers
    //    length:      the length of array numbers
    //    duplication: (Output) the duplicated number in the array number,length of duplication array is 1,so using duplication[0] = ? in implementation;
    //                  Here duplication like pointor in C/C++, duplication[0] equal *duplication in C/C++
    //    这里要特别注意~返回任意重复的一个，赋值duplication[0]
    // Return value:       true if the input is valid, and there are some duplications in the array number
    //                     otherwise false
    public boolean duplicate(int numbers[], int length, int[] duplication) {

        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < length; i++) {
            boolean add = set.add(numbers[i]);
            if (!add) {
                duplication[0] = numbers[i];
                break;
            }
        }

        return duplication[0] > 0;
    }

}
